In many clinical situations it is essential to know the exact location of the tip of a catheter inserted in the body of a patient. It is also very helpful to be able to navigate the catheter through the patient's body, i.e., to follow the movements of the catheter tip, e.g., during catheter insertion. Currently, fluoroscopy can be used for catheter navigation and tip location of intravascular catheters. In the case of central venous catheters, navigation support is currently provided by methods, such as fluoroscopy, magnetic, or Doppler-based which have each their own benefits and limitations. ECG-based methods are used currently only for catheter tip location at the cavo-atrial junction in the proximity of the sinoatrial node. ECG-based methods are currently not used for catheter navigation.
There exists currently a need for an accurate, safe, intra-procedural and easy-to-use device, which allows, in a single device, for navigation and tip location of catheters at different locations in the vasculature, in the venous as well as in the arterial systems, which works for a wide range of catheter types and clinical applications, and which does not use radiation-based methods like X-ray and fluoroscopy.
A system and method for catheter mapping is described in U.S. Pat. No. 5,983,126, which uses a catheter equipped with at least a measuring electrode and a reference electrode on the patient to which triangulation signals are applied such that the a three-dimensional location of the catheter tip within the body can be calculated. U.S. Pat. No. 8,155,732 describes an ECG system for ECG signal measurement of intracardiac ECG using a switch and a processor to amplify the difference of a chest lead signal electronically connected to a catheter and a patient limb ECG signal in order to provide a catheter tip location signal without using any other surface ECG leads. U.S. Pat. No. 8,388,541 describes an integrated catheter placement system, which uses a magnetic tip location sensor for temporary placement on the patient's chest to detect the magnetic field of a stylet disposed in the a lumen of the catheter.